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| United States Patent |
5,306,008
|
|
Kinoshita
|
April 26, 1994
|
Momentum transfer golf club
Abstract
This invention relates to a category of golf clubs ranging from the driver
to a seven wood, and ranging from a one iron to high lofted sand wedges.
Improved performance is achieved by giving proper consideration to the
difference in the velocity of the club head toe relative to the velocity
of the heel at impact. Also, to achieve improved transfer of the club head
momentum to the golf ball, this invention uses a high moment of inertia
interconnect 21 traversing through, or along, the horizontal plane
intersecting the club head effective center of gravity, wherein said beam
rigidly interconnects the heel-toe mass sections. These improvements will
enhance the playability of these golf clubs by providing golf clubs
affording increased distance with less dispersion.
| Inventors:
|
Kinoshita; Frank (P.O. Box 3164, Rancho Santa Fe, CA 92067)
|
| Appl. No.:
|
940460 |
| Filed:
|
September 4, 1992 |
| Current U.S. Class: |
473/242; 473/349 |
| Intern'l Class: |
A63B 053/04 |
| Field of Search: |
273/167 R-167 K,77 R,77 A,164.1,187.6,80 A
|
References Cited
U.S. Patent Documents
| 1133129 | Mar., 1915 | Govan | 273/171.
|
| 1485272 | Feb., 1924 | Kinsman | 273/164.
|
| 1503291 | Jul., 1924 | Rimmer | 273/169.
|
| 1525148 | Feb., 1925 | Pickop | 273/167.
|
| 1654916 | Jan., 1928 | Boyce | 273/168.
|
| 1671956 | May., 1928 | Sime | 273/169.
|
| 1969086 | Aug., 1934 | Luckett | 273/164.
|
| 1993982 | Mar., 1935 | Glover | 273/167.
|
| 2842369 | Jul., 1958 | East | 273/164.
|
| 2859972 | Nov., 1958 | Reach | 273/164.
|
| 3042405 | Jul., 1962 | Solheim | 273/168.
|
| 3059926 | Oct., 1962 | Johnstone | 273/77.
|
| 3212783 | Oct., 1965 | Bradley et al. | 273/167.
|
| 3860244 | Jan., 1975 | Cosby | 273/167.
|
| 3873094 | Mar., 1975 | Sebo et al. | 273/167.
|
| 3941390 | Mar., 1976 | Hussey | 273/169.
|
| 3947041 | Mar., 1976 | Barber | 273/167.
|
| 3955820 | May., 1976 | Cochran | 273/167.
|
| 3980301 | Sep., 1976 | Smith | 273/80.
|
| 4063737 | Dec., 1977 | Tom | 273/174.
|
| 4214754 | Jul., 1980 | Zebelean | 273/167.
|
| 4247105 | Jan., 1981 | Jeghers | 273/77.
|
| 4322083 | Mar., 1982 | Imai | 273/167.
|
| 4417731 | Nov., 1983 | Yamada | 273/167.
|
| 4420156 | Dec., 1983 | Campau | 273/77.
|
| 4444395 | Apr., 1984 | Reiss | 273/171.
|
| 4471961 | Sep., 1984 | Masghati | 273/175.
|
| 4512577 | Apr., 1985 | Solheim | 273/77.
|
| 4553755 | Nov., 1985 | Yamada | 273/171.
|
| 4607846 | Aug., 1986 | Perkins | 273/167.
|
| 4621813 | Nov., 1986 | Solheim | 273/77.
|
| 4650191 | Mar., 1987 | Mills | 273/169.
|
| 4762322 | Aug., 1988 | Molitor | 273/77.
|
| 4826172 | May., 1989 | Antonious | 273/167.
|
| 4828266 | May., 1989 | Tunstall | 273/167.
|
| 4854581 | Aug., 1989 | Long | 273/77.
|
| 4869507 | Sep., 1989 | Sahm | 273/171.
|
| 4872684 | Oct., 1989 | Dippel | 273/167.
|
| 4895367 | Jan., 1990 | Kajita | 273/77.
|
| 4962932 | Oct., 1990 | Anderson | 273/171.
|
| 5072941 | Dec., 1991 | Klein | 273/174.
|
| 5094457 | Mar., 1992 | Kinoshita | 273/167.
|
| 5131656 | Jul., 1992 | Kinoshita | 273/164.
|
| Foreign Patent Documents |
| 376277 | Jun., 1932 | GB | 273/164.
|
| 439187 | Dec., 1935 | GB | 273/171.
|
Primary Examiner: Graham; Mark S.
Assistant Examiner: Passaniti; Sebastiano
Claims
I claim is:
1. A golf club comprising a rigid club head, a shaft and a grip;
said club head being rigidly shaped to define a club face, a heel, a sole,
a toe, a crown, and a hosel, a heel section, a toe section, a toe mass
section, a heel mass section, and an interconnect;
said club face having a front being adapted to strike a golf ball;
said club face having upper and lower edges, toe and heel boundary limits;
said heel being the portion of said club head where the sole and hosel
meet;
said sole defining a bottom surface of said club head which normally rests
on the ground when said golf club is held in the address position;
said toe being the part of the club head that is the farthest away from
said heel of said club head;
said crown defining a curved top portion of said club head;
said hosel being that portion of said club head that is designed to
interfit with said shaft;
said hosel being integrally attached to said club head;
said club head having an effective center of gravity substantially at the
midpoint of the toe and heel boundary limits of said club face;
said heel section being the portion, of said club head, having boundary
limits starting at a vertical plane intersecting the effective center of
gravity and ending at a heel extremity;
said toe section being the portion, of said club head, having boundary
limits starting at a vertical plane intersecting the effective center of
gravity and ending at a toe extremity;
said vertical plane being perpendicular to said club face;
said effective center of gravity affording dynamic balancing so that the
moment of the toe section momentum equals the moment of the heel section
momentum at impact;
said heel section having a weight of from 1.05 to 1.15 greater than the
weight of said toe section;
said toe mass section having a concentrated weight of from 7 to 30 percent
of the weight of said club head and being located at the proximity of the
toe;
said heel mass section having a concentrated weight of from 10 to 33
percent of the weight of said club head and being located at the proximity
of the heel;
said interconnect rigidly connecting said toe mass section to the heel mass
section, traversing substantially through a horizontal plane intersecting
said effective center of gravity;
said interconnect being an intrinsic part of said club head and having a
rearward dimension measured horizontally from the club face along said
vertical plane of at least 0.5 inch affording a high moment of inertia
interconnect;
said grip being adhesively attached to said shaft; and
said shaft being attached to said club head.
2. The golf club of claim 1, wherein said crown of said club head has a
mark or plurality of marks indicating the locus or loci between said
vertical plane and the top portion of said crown.
3. The golf club of claim 1, wherein said club face has a distinguishing
mark or plurality of marks indicating the location of said effective
center of gravity as viewed from the front of said club face.
4. The golf club of claim 1, wherein said crown of said club head has a
mark or plurality of marks indicating the locus or loci between said
vertical plane and the top portion of said crown, and wherein said club
face has a distinguishing mark or plurality of marks indicating the
location of said effective center of gravity as viewed from the front of
said club face.
5. The golf club of claim 1, wherein the club face has a roll radius of 8
inches to 50 inches and a bulge radius of 8 inches to 50 inches.
6. A golf club comprising a rigid club head, a shaft and a grip;
said club head being rigidly shaped to define a club face, a heel, a sole,
a toe, a crown, and a hosel, a heel section, a toe section;
said club face having a front being adapted to strike a golf ball;
said club face having upper and lower edges, toe and heel boundary limits;
said heel being the portion of said club head where the sole and hosel
meet;
said sole defining a bottom surface of said club head which normally rests
on the ground when said golf club is held in the address position;
said toe being the part of the club head that is the farthest away from
said heel of said club head;
said crown defining a curved top portion of said club head;
said hosel being that portion of said club head that is designed to
interfit with said shaft;
said hosel being integrally attached to said club head;
said club head having an effective center of gravity substantially at the
midpoint of the toe and heel boundary limits of said club face;
said heel section being the portion, of said club head, having boundary
limits starting at a vertical plane intersecting the effective center of
gravity and ending at a heel extremity;
said toe section being the portion, of said club head, having boundary
limits starting at a vertical plane intersecting the effective center of
gravity and ending at a toe extremity;
said vertical plane being perpendicular to said club face;
said effective center of gravity affording dynamic balancing so that the
moment of the toe section momentum equals the moment of the heel section
momentum at impact;
said heel section having a fixed non-adjustable configuration affording a
weight of from 1.05 to 1.15 greater than a fixed non-adjustable weight of
said toe section so that the moment of the heel section momentum equals
the moment of the toe section momentum at impact;
said heel section momentum being derived by due consideration to the
different velocity of the toe and heel sections at impact;
said toe section momentum being derived by due consideration to the
different velocity of the toe and heel sections at impact;
said grip being adhesively attached to said shaft; and
said shaft being attached to said club head.
7. The golf club of claim 6, wherein said crown of said club head has a
mark or plurality of marks indicating the locus or loci between said
vertical plane and the top portion of said crown.
8. The golf club of claim 6, wherein said club face has a distinguishing
mark or plurality of marks indicating the location of said effective
center of gravity as viewed from the front of said club face.
9. The golf club of claim 6, wherein said crown of said club head has a
mark or plurality of marks indicating the locus or loci between said
vertical plane and the top portion of said crown, and wherein said club
face has a distinguishing mark or plurality of marks indicating the
location of said effective center of gravity as viewed from the front of
said club face.
10. The golf club of claim 6, wherein the club face has a roll radius of 8
inches to 50 inches and a bulge radius of 8 inches to 50 inches.
11. A golf club head;
said club head being rigidly shaped to define a club face, a heel, a sole,
a toe, a crown, and a hosel, a heel section, a toe section, a toe mass
section, a heel mass section, and an interconnect;
said club face having a front being adapted to strike a golf ball;
said club face having upper and lower edges, toe and heel boundary limits;
said heel being the portion of said club head where the sole and hosel
meet;
said sole defining a bottom surface of said club head which normally rests
on the ground when said golf club is held in the address position;
said toe being the part of the club head that is the farthest away from
said heel of said club head;
said crown defining a curved top portion of said club head;
said hosel being that portion of said club head that is designed to
interfit with said shaft;
said hosel being integrally attached to said club head;
said club head having an effective center of gravity substantially at the
midpoint of the toe and heel boundary limits of said club face;
said heel section being the portion, of said club head, having boundary
limits starting at a vertical plane intersecting the effective center of
gravity and ending at a heel extremity;
said toe section being the portion, of said club head, having boundary
limits starting at a vertical plane intersecting the effective center of
gravity and ending at a toe extremity;
said vertical plane being perpendicular to said club face;
said effective center of gravity affording dynamic balancing so that the
moment of the toe section momentum equals the moment of the heel section
momentum at impact;
said heel section having a weight of from 1.05 to 1.15 greater than the
weight of said toe section;
said toe mass section having a concentrated weight of from 7 to 30 percent
of the weight of said club head and being located at the proximity of the
toe;
said heel mass section having a concentrated weight of from 10 to 33
percent of the weight of said club head and being located at the proximity
of the heel;
said interconnect rigidly connecting said toe mass section to the heel mass
section, traversing substantially through a horizontal plane intersecting
said effective center of gravity;
said interconnect being an intrinsic part of said club head and having a
rearward dimension measured horizontally from the club face along said
vertical plane of at least 0.5 inch affording a high moment of inertia
interconnect;
12. The golf club of claim 11, wherein said crown of said club head has a
mark or plurality of marks indicating the locus or loci between said
vertical plane and the top portion of said crown.
13. The golf club of claim 11, wherein said club face has a distinguishing
mark or plurality of marks indicating the location of said effective
center of gravity as viewed from the front of said club face.
14. The golf club of claim 11, wherein said crown of said club head has a
mark or plurality of marks indicating the locus or loci between said
vertical plane and the top portion of said crown, and wherein said club
face has a distinguishing mark or plurality of marks indicating the
location of said effective center of gravity as viewed from the front of
said club face.
15. The golf club of claim 11, wherein the club face has a roll radius of 8
inches to 50 inches and a bulge radius of 8 inches to 50 inches.
16. A golf club head;
said club head being rigidly shaped to define a club face, a heel, a sole,
a toe, a crown, and a hosel, a heel section, a toe section;
said club face having a front being adapted to strike a golf ball;
said club face having upper and lower edges, toe and heel boundary limits;
said heel being the portion of said club head where the sole and hosel
meet;
said sole defining a bottom surface of said club head which normally rests
on the ground when said golf club is held in the address position;
said toe being the part of the club head that is the farthest away from
said heel of said club head;
said crown defining a curved top portion of said club head;
said hosel being that portion of said club head that is designed to
interfit with said shaft;
said hosel being integrally attached to said club head;
said club head having an effective center of gravity substantially at the
midpoint of the toe and heel boundary limits of said club face;
said heel section being the portion, of said club head, having boundary
limits starting at a vertical plane intersecting the effective center of
gravity and ending at a heel extremity;
said toe section being the portion, of said club head, having boundary
limits starting at a vertical plane intersecting the effective center of
gravity and ending at a toe extremity;
said vertical plane being perpendicular to said club face;
said effective center of gravity affording dynamic balancing so that the
moment of the toe section momentum equals the moment of the heel section
momentum at impact;
said heel section having a fixed non-adjustable configuration affording a
weight of from 1.05 to 1.15 greater than a fixed non-adjustable weight of
said toe section so that the moment of the heel section momentum equals
the moment of the toe section momentum at impact;
said heel section momentum being derived by due consideration to the
different velocity of the toe and heel sections at impact;
said toe section momentum being derived by due consideration to the
different velocity of the toe and heel sections at impact.
17. The golf club of claim 16, wherein said crown of said club head has a
mark or plurality of marks indicating the locus or loci between said
vertical plane and the top portion of said crown.
18. The golf club of claim 16, wherein said club face has a distinguishing
mark or plurality of marks indicating the location of said effective
center of gravity as viewed from the front of said club face.
19. The golf club of claim 16, wherein said crown of said club head has a
mark or plurality of marks indicating the locus or loci between said
vertical plane and the top portion of said crown, and wherein said club
face has a distinguishing mark or plurality of marks indicating the
location of said effective center of gravity as viewed from the front of
said club face.
20. The golf club of claim 16, wherein the club face has a roll radius of 8
inches to 50 inches and a bulge radius of 8 inches to 50 inches.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a category of golf equipment known as an
iron or a wood golf club. There is clearly a continuing need for
improvement in the playability of golf equipment. As well known to those
who know the game of golf, generally the strokes taken to get the ball on
the green accounts for more than half of a golfer's total score. It is the
intent of the present invention to provide the golfer with iron and wood
clubs affording dynamic balancing with respect to the expected impact
point. Also to provide improved transfer of the club head momentum to the
golf ball. These improvements, dynamic balancing and improved momentum
transfer will aid the golfer in propelling the golf ball towards the
green. The present invention's goal is to reduce the number of strokes
taken by the golfer to complete a round of golf. Toward this end, the golf
club constraints are broad as far as the golf club head material, weight,
loft and lie angles are concerned. The golf club woods will range from a
number one wood to a number seven wood. The golf club irons will range
from a number one iron to high-lofted sand wedges.
OBJECT OF THE INVENTION
To provide golf clubs that afford dynamic balancing with respect to the
expected impact point. Also, to provide golf clubs affording improved
transfer of the golf club head momentum to the golf ball. The golf clubs
of the present invention afford superior playing characteristics compared
to prior art golf clubs. The dynamic balancing of the golf club head or
improved momentum transfer affords longer distance with less dispersion in
the flight of the golf ball. Said superior playing characteristics are
obtained by employing the features discussed herein:
(A) To provide club heads that utilize unique dynamic balancing with
respect to the expected impact point. The expected impact point will be
located on the vertical plane intersecting the midpoint of the heel and
toe boundary limits of the club face. Dynamic balancing is obtained by
taking into consideration the different velocities associated with
different parts of the club head at impact. In a delayed hit golf swing,
the toe section center of gravity velocity will be approximately 10
percent greater than the heel section center of gravity velocity at the
time of impact. The delayed hit golf swing is defined as a golf swing that
exhibit these conditions. The golfer maintains a cocked wrist position
until approximately the last 90 degrees of swing arc just prior to impact,
and in this cocked wrist position the club face is parallel to and on the
swing plane, and at impact the club face is perpendicular to the swing
plane. In other words, the golfer is force to rotate the club shaft 90
degrees, during the last 90 degrees of swing arc, to bring the club head
into the proper hitting position. U.S. Pat. No. 5,094,457, page 3 also
defines the delayed hit. Also to achieve dynamic balancing, the actual
moment of the momentums of the heel and toe sections are set to be equal.
As a first order approximation, empirical data shows that the initial
velocity of the golf ball is a function of the club head velocity. Also,
the initial velocity of tbe the golf ball can be expressed as a function
of club head momentum mv.
m=club head mass.
v=velocity of club head.
Since the golfer is seeking a "twist free" condition at impact, the club
head is designed so that the moment of the toe section momentum is equal
to moment of the heel section momentum. In equation form,
M.sub.T .times.m.sub.T v.sub.T =M.sub.H .times.m.sub.H v.sub.H.
M.sub.T =moment of the toe section=distance from the toe section center
gravity to the vertical plane intersecting the effective center of gravity
of the club head, wherein said vertical plane is perpendicular to the club
face.
m.sub.T =mass of the toe section.
v.sub.T =velocity of the toe section at impact.
M.sub.H =moment of the heel section=distance from the heel section center
gravity to the vertical plane intersecting the effective center of gravity
of the club head, wherein said vertical plane is perpendicular to the club
face.
m.sub.H =mass of the heel section.
v.sub.H =velocity of the heel section at impact.
The equation M.sub.T .times.m.sub.T v.sub.T =M.sub.H .times.m.sub.H v.sub.H
defines dynamic balancing for the present invention. Since all club heads
of the present invention afford dynamic balancing, playability of these
clubs will be enhanced by affording longer distance with less dispersion.
(B) To further enhance the playability of the golf clubs of the present
invention, the longer clubs (smaller numbered clubs) are designed to
provide a lesser amount of rotational moment of inertia about the shaft
longitudinal axis. Since the lesser amount of rotational moment of inertia
for longer clubs will be offset (compensated) by the higher centrifugal
force generated by the higher velocity of the longer clubs, the rotational
force required by the golfer, to bring the club head into the hitting
position, will be substantially constant for all clubs.
(C) To provide golf clubs or club heads that have an unique interconnect
beam. This unique interconnect beam is used to rigidly interconnect the
heel and toe mass sections. This unique interconnect beam is a structure
affording high moment of inertia along the club head's front to back
dimension. At substantially the mid-point of the heel and the toe mass
sections, the beam traverses through the horizontal plane intersecting the
club head's effective center of gravity. Since the heel and toe mass
sections are rigidly interconnected to each other through this high moment
of inertia beam, improved transfer of the heel and toe mass momentum to
the golf ball will be realized compared to prior art golf clubs. Prior art
heel and toe weighted golf club heads are devoid of a high moment of
inertia beam, wherein said beam traverses through, or along, the
horizontal plane intersecting the center of gravity. Prior art seems to
imply that the momentum of the heel and toe mass will be transferred to
the golf ball through the sole flange, through the thin striking face
plate, and/or through the rim of the club head. Specifically, U.S. Pat.
Nos. 4,420,156 and 4,621,813 do not describe or claim a high moment of
inertia beam which passes through, or along, the horizontal plane
intersecting the club head center of gravity. I am not aware of any prior
art, either in patents or the marketplace, where a heel-toe weighted golf
club head utilizes a truly high moment of inertia beam to interconnect the
heel-toe mass sections, wherein the beam traverses through, or along, the
horizontal plane intersecting the club head center of gravity. The present
invention's high moment of inertia beam aids the attainment of a truly
rigid connection of the heel and toe mass sections so that improved
transfer of the heel-toe mass momentum to the golf ball will be realized.
(D) To provide an unique heel-toe weighted golf club head configuration
that truly affords a high radius of gyration. Radius of gyration is well
discussed in U.S. Pat. No. 4,420,156. High radius of gyration will reduce
the adverse effects of directional loss and momentum transfer loss caused
by off-centered impacts along the heel-toe dimension. Since the present
invention's unique heel-toe weighted sections are rigidly attached to each
other through its high moment of inertia beam structure, a large sweet
spot along the heel-toe dimension is realized. The center of gravity of
the high moment of inertia beam, heel and toe mass sections is uniquely
located on the horizontal plane intersecting the center of gravity of the
remainder of the club head. In other words, there is correspondence
between the center of gravities of these two components of the club head.
(E) To provide a high moment of inertia interconnect beam that forms a
rigid connection between the heel-toe weighted sections and the impact
point. The term moment of inertia as applied to the interconnect beam
could be referred to as the "second moment of area", but since the term
moment of inertia is used in beam deflection analysis, the term moment of
inertia will be used here. In other words, when the term moment of inertia
is used in conjunction the term interconnect beam, interconnect,
interconnect structure, or beam, we mean the "second moment of area". Said
interconnect beam is thin in the vertical dimension in order to keep its
weight at a minimum, but is wide in the front to back dimension to obtain
high front to back moment of inertia. In beam analysis,
deflection=5w1.sup.4 /384EI for the case where the beam is supported on
both ends. E=Modulus of Elasticity. Modulus of Elasticity of steel is
approximately 29,000,000 psi. I=moment of inertia=bh.sup.3 /12, b is the
vertical thickness of the interconnect beam, h is the rearward dimension
of the interconnect beam. It can be seen from the beam deflection equation
given above that for a given set of conditions, deflection is inversely
proportional to the moment of inertia. Since the moment of inertia of the
interconnect beam is related to the cube power of its rearward dimension,
it is essential that a large rearward dimension be maintained to realize a
club head affording negligible deflection. With an ideal golf stroke and
zero deflection, all of the heel-toe mass momentum will be transferred to
the golf ball. Without a high moment of inertia interconnect beam,
deflection of the club head will occur with loss of momentum transfer.
Hence, it is imperative that a high moment of inertia interconnect beam be
utilized.
A high radius of gyration club head that does not rigidly interconnect its
heel-toe mass sections, does not afford an elongated sweet spot along the
heel-toe dimension. An authority states that: "For golf balls contacted
more than 1/4 inch from the sweet spot while the other parameters were in
perfect order, putts of 8 feet or greater would miss 95 percent of the
time."[Dave Pelz in Putt Like The Pros, Harper Perennial (1989), p 71].
This statement emphasizes the need for a high radius of gyration club head
that undergoes a negligible amount of deflection at impact. Dave Pelz's
statement refers to putts, but it is just as important, if not more
important, to have a truly high radius of gyration wood and iron club
heads designed for impulse conditions. It appears that prior art has
ignored the importance or using a high moment of inertia beam to
interconnect the heel-toe mass sections, wherein said beam traverses
through, or along, the horizontal plane intersecting the center of
gravity.
(F) In one embodiment of the present invention, to further facilitate the
use of the golf clubs, a mark or marks will be placed on the crown to
indicate the locus or loci of the vertical plane intersecting the
effective center of gravity and the surface of the crown. Alternately, or
in conjunction with the crown mark(s), marking or markings will be located
on the club face to show the location of the effective center of gravity
as viewed from the front of the club face. All mark(s) will be downwardly
visible from the top of the club head.
(G) It is not universally recognized (see U.S. Pat. No. 4,322,083 FIG. 3)
that maximum momentum is transferred to the golf ball when the club head
center of gravity is located on a horizontal plane behind the impact
point. U.S. Pat. No. 5,131,656, FIG. 6, page 10 shows that when the club
head center of gravity is on the same horizontal plane as the impact
point, maximum momentum is transferred to the golf ball.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a golf club comprised
of a club head, a shaft, and a grip; or just a club head. Said club head
is rigidly shaped to define a club face, a heel, a sole, a toe, a crown
(top surface), a hosel, a heel section, and a toe section. In one
embodiment, said club head will also be rigidly shaped to define a heel
mass section, a toe mass section, and an interconnect beam. The heel mass
section, the toe mass section, and the interconnect beam will not be
visible from the outside in the case of hollow wood clubs.
The present invention's golf clubs or club heads affords dynamic balancing
in regards to the expected impact point. The expected impact point will be
located on the vertical plane intersecting the midpoint of the heel and
toe boundary limits of the club face, wherein said vertical plane is
perpendicular to the club face. Dynamic balancing is obtained by taking
into consideration the different velocities associated with different
parts of the club head at impact. In a delayed hit golf swing, the toe
section center of gravity velocity will be approximately 10 percent
greater than heel section center of gravity velocity at the time of
impact. Given that the club head is a rigid body and that the club shaft
is rotated 90 degrees during the last 90 degrees of swing arc just prior
to impact, the club head toe velocity must be greater than the club head
heel velocity at impact. In other words, since the club head toe has to
"catch-up" to the club head heel during the delayed hit, the club head toe
velocity has to be greater than the club head heel velocity at impact. In
fact the difference in the toe-heel center of gravity velocities is
approximated by:
2[(3.14159/2)r.sub.T -(3.14159/2)r.sub.H ]/t=difference in feet/second.
r.sub.T =distance in feet measured along the horizontal plane from the
longitudinal shaft axis to the toe section center of gravity.
r.sub.H =distance in feet measured along the horizontal plane from the
longitudinal shaft axis to the heel section center of gravity.
t=time in seconds from the time golfer first entered the delayed hit zone
(90 degrees of swing arc just prior to impact) to the time of impact.
Using the case where the average club head velocity in the delayed hit
zone is 75 MPH (110 feet/second), the time spent in the delayed hit
zone=0.057 seconds. If r.sub.T =2.35 inches=0.196 feet and r.sub.H =zero,
we have 2[(3.14159/2)0.196]/0.057=10.80 feet/second. Stating this
difference as a ratio, we have (110+10.80)/110=1.098. Dynamic balancing is
the case when the toe section moment of momentum equals the heel section
moment of momentum, wherein the moments are referenced to the vertical
plane intersecting the effective center of gravity. In equation form,
M.sub.T .times.m.sub.T v.sub.T =M.sub.H .times.m.sub.H v.sub.H.
M.sub.T =moment of the toe section=distance from the toe section center
gravity to the vertical plane intersecting the effective center of gravity
of the club head, wherein said vertical plane is perpendicular to the club
face.
m.sub.T =mass of the toe section.
v.sub.T =velocity of the toe section at impact.
M.sub.H =moment of the heel section=distance from the heel section center
gravity to the vertical plane intersecting the effective center of gravity
of the club head, wherein said vertical plane is perpendicular to the club
face.
m.sub.H =mass of the hell section.
v.sub.H =velocity of the heel section at impact.
Since all club heads of the present invention afford dynamic balancing,
playability of these clubs will be enhanced yielding longer distance with
less dispersion.
To provide a golf club that affords improved transfer of the club head
momentum to the golf ball compared to prior art golf clubs. This improved
momentum transfer will provide increased distance with less dispersion.
This improved momentum transfer is achieve by using a high moment of
inertia beam to rigidly interconnect the heel mass section to the mass
sections. At substantially the mid-point of the heel and the toe mass
sections, the beam traverses through the horizontal plane intersecting the
club head's effective center of gravity. The heel and toe mass sections,
and the interconnect beam is intrinsic to the club head. Since the heel
and toe mass sections are rigidly interconnected to each other through
this high moment of inertia beam, improved transfer of the heel and toe
mass momentum to the golf ball will be realized. Prior art heel and toe
weighted golf club heads are devoid of a high moment of inertia beam,
wherein said beam traverses through, or along, the horizontal plane
intersecting the center of gravity.
To provide an unique heel-toe weighted golf club head configuration that
truly affords a high radius of gyration. Radius of gyration is well
discussed in U.S. Pat. No. 4,420,156. High radius of gyration of a truly
rigid body will reduce the adverse effects of directional loss and
momentum transfer loss caused by off-centered impacts along the heel-toe
dimension. Since the present invention's unique heel-toe weighted sections
are rigidly attached to each other through its high moment of inertia
beam, an elongation of the sweet spot along the heel-toe dimension is
realized. The moment of inertia of a beam is define as: I=bh.sup.3 /12. In
the present invention, b is the vertical thickness of the interconnect
beam, and h is the rearward dimension of the interconnect beam (note that
the effect of h is to the cube power). Since it is imperative that a high
moment of inertia beam be utilized to minimize deflection at impact, the
present invention specifies a minimum rearward (h) dimension of 0.5 inch.
For the present invention a high moment of inertia beam is defined as a
beam having a rearward dimension of not less than 0.5 inch. A high radius
of gyration club head that does not rigidly interconnect its heel-toe mass
sections, can not afford a maximized elongation of the sweet spot along
the heel-toe dimension.
To further facilitate the use of the present invention's golf clubs, a mark
or marks will be placed on the crown to indicate the locus or loci of the
vertical plane intersecting the effective center of gravity and the
surface of the crown. Alternately, or in conjunction with the crown
mark(s), marking or markings will be located on the club face to show the
location of the effective center of gravity as viewed from the front of
the club face.
Dynamic balancing coupled with improved momentum transfer of these golf
clubs of the present invention will provide superior and unique playing
characteristic compared to prior art golf clubs due to the unique features
listed as follows:
(a) Dynamic balancing of the club head is provided so that the effective
center of gravity is located on a vertical plane intersecting the midpoint
of the heel and toe boundary limits of the club face, wherein said
vertical plane is perpendicular to then club face.
(b) A high moment of inertia beam is used to rigidly interconnect the heel
and toe mass sections so that a club head affording negligible deflection
at impact is provided.
(c) The high moment of inertia beam location is constrained so that at its
midpoint, it passes through the horizontal plane intersecting the
effective club head center of gravity so that improved momentum transfer
to the golf ball is realized.
(d) Marking(s) is(are) provided on the crown and/or the club face to
indicate the location of the effective club head center of gravity to
further facilitate the golfer use of the golf clubs of the present
invention.
(e) The longer clubs are designed to provide lesser amounts of rotational
moment of inertia about the shaft axis. Due to the compensating effect of
the higher centrifugal force associated with longer clubs, the rotational
force exerted by the golfer will appear to be substantially the same for
all clubs.
The unique features of the golf club or club head that are considered
characteristic of the present invention are set forth in the appended
claims. The invention will readily be understood from the following
description when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a moment of momentum diagram for the heel and toe sections as
related to a wood club head and a front view of the wood club head of the
present invention.
FIG. 2 is a plan view of the diagram shown in the upper half of FIG. 1 and
shows the heel and toe section moments of momentums in relationship to the
effective center of gravity, or the expected point of reaction of a golf
ball.
FIG. 3 is frontal view of the interconnect beam, heel and toe mass sections
of a wood club head of the present invention.
FIG. 4 is a sectional view of the interconnect beam, heel and toe mass
sections of a wood club head taken at the horizontal plane intersecting
the effective club head center of gravity.
FIG. 5 is a front view of a number three iron of the present invention.
FIG. 6 is a sectional view of the interconnect beam, heel and toe mass
sections of a number three iron club head, taken at the horizontal plane
intersecting the effective club head center of gravity.
FIG. 7 is a sectional view of the number three iron club head taken at the
vertical plane passing through its effective center of gravity.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, the bottom half is a front view of the club face and
the upper half is a diagram of the moment of momentum diagram for the heel
and toe sections as related to a wood club head, wherein the moments are
relative to the effective club head center of gravity 20. Center of
gravity 20, the club head toe section center of gravity 19, and the heel
section center of gravity 34 are projected onto the upper half of FIG. 1
to form the moment of momentum diagram. The momentum m.sub.T v.sub.T 10 is
toward the viewer of the drawing and is multiplied by the distance 13 to
obtain its moment of momentum. The momentum m.sub.H v.sub.H 12 is toward
the viewer of the drawing and is multiplied by the distance 14 to obtain
its moment of momentum.
m.sub.T =mass of the toe section.
v.sub.T =velocity of the toe section at impact.
m.sub.H =mass of the heel section.
v.sub.H =velocity of the heel section at impact.
The reaction of the golf ball 11 which is coincident to the vertical plane
23 is away from the viewer of the drawing and is the balance point for the
moments of momentums generated by the momentums 10, 12, and the distances
13, 14. To obtain dynamic balancing as discussed in this disclosure,
M.sub.T .times.m.sub.T v.sub.T =M.sub.H .times.m.sub.H v.sub.H.
M.sub.T =moment of the toe section=distance from the toe section center
gravity to the vertical plane intersecting the effective center of gravity
of the club head, wherein said vertical plane is perpendicular to the club
face.
m.sub.T =mass of the toe section.
v.sub.T =velocity of the toe section at impact.
M.sub.H =moment of the heel section=distance from the heel section center
gravity to the vertical plane intersecting the effective center of gravity
of the club head, wherein said vertical plane is perpendicular to the club
face.
m.sub.H =mass of the heel section.
v.sub.H =velocity of the heel section at impact.
The difference in the heel section center of gravity velocity and the toe
section center of gravity velocity is equal to:
2[(3.14159/2)r.sub.T -(3.14159/2)r.sub.H ]/t=difference in feet/second.
r.sub.T =distance 31 in feet measured along the horizontal plane from the
longitudinal shaft axis to the toe section center of gravity.
r.sub.H =distance 32 in feet measured along the horizontal plane from the
longitudinal shaft axis to the heel section center of gravity.
Using FIG. 1 as a basis, r.sub.T =1.96 inches and r.sub.H =-0.127 inch.
t=time in seconds from the time golfer first entered the delayed hit zone
(90 degrees of swing arc just prior to impact) to the time of impact.
During the time t, the club head has undergone a rotation of 90 degrees
about its longitudinal shaft axis. Using the case where the average club
head velocity in the delayed hit zone is 75 MPH (110 feet/second), the
time spent in the delayed hit zone is 0.057 seconds.
Since r.sub.T =1.96 inches=0.163 feet and
r.sub.H =-0.127 inch=-0.0106 feet,
2[(3.14159/2)(0.163)-(3.14159/2)(-0.0106)]/0.057=9.57 feet/second.
The velocities of a rigid body can at any instant be described as the sum
of the velocity of a reference point of the body plus a velocity due to
rotation about an axis through the reference point. In this case, the club
head is the rigid body and the longitudinal shaft axis intercept 33 of the
horizontal plane 18 is said reference point. Individually the velocities
are;
[2[(3.14159/2)(0.163)]/0.057+110] feet/second=119 feet/second for the toe
section center of gravity velocity, and
[2[(3.14159/2)(-0.0106)]/0.057+110] feet/second=109.4 feet/second for the
heel section center of gravity velocity.
Using FIG. 1 as a basis, distance 10 is 1.02 inches and distance 12 is 1.10
inches. For a "twist free" condition at impact, m.sub.T
.times.119.times.1.02=m.sub.H .times.109.4.times.1.10. Or m.sub.H =1.009
m.sub.T. In other words, in this case, to have dynamic balancing, the mass
of the heel section must be sightly greater than the mass of the toe
section. The longitudinal shaft axis 17 is shown to intersect the
horizontal plane 18 at point 33 which is marked with an X. The effective
club head center of gravity 20 and the vertical plane 23 is shown to be
equidistant 15 from the club face 16 heel boundary limit 45 and the toe
boundary limit 41. The club head heel is shown as 46 and the club head toe
is shown as 40. The hosel is shown as 44, the crown is shown as 35, the
crown marking is shown as 42, and the club face marking is shown as 43.
FIG. 2 is a plan view of the diagram shown in the upper half of FIG. 1 and
shows the heel and toe section moments of momentums in relationship to the
reaction of a golf ball 11 which is coincident to vertical plane
intersecting the effective center of gravity. The diagram shows the
instantaneous situation at impact. It had been determined that the
velocity of momentum 10 was 119/109.4 times greater than the velocity of
momentum 12 for the case that was analyzed above.
FIG. 3 is frontal view of the interconnect beam, heel and toe mass sections
of a wood club head of the present invention. The high moment of inertia
beam 21 is shown interconnecting the toe section 30 to the heel section
22. The high inertia beam 21 is shown traversing along the horizontal
plane 18 intersecting the effective club head center of gravity 20. The
vertical plane 23 intersecting the effective center of gravity 20 is
perpendicular to the club face 16.
FIG. 4 is a sectional view of the interconnect beam 21, heel mass section
22 and toe mass section 30 of a wood club head taken at the horizontal
plane intersecting the effective club head center of gravity 20. As shown
here, with hollow wood clubs, the effective center of gravity 20 will be
located on the vertical plane 23 and behind the high moment of inertia
beam 21. The moment of inertia of a beam is define as: I=bh.sup.3 /12. In
the present invention, b is the vertical thickness of the interconnect
beam, and h is the rearward dimension 24 relative the club face 16 as
shown in this sectional view. Since it is imperative that a high moment of
inertia beam be utilized to minimize deflection at impact, the present
invention specifies a minimum rearward h dimension 24 of 0.5 inch. Note
that the moment of inertia of a beam is a function of h to the cube power.
A high radius of gyration club head that does not rigidly interconnect its
heel-toe mass sections, can not afford a maximized elongation of the sweet
spot along the heel-toe dimension.
FIG. 5 is a front view of a number three iron of the present invention. The
club head effective center of gravity 20 and the vertical plane 23 bisects
the club face 16. The horizontal plane 18 is shown intersecting the
effective center of gravity 20. The crown is shown as 35, the crown
marking is shown as 42, and the club face marking is shown as 43.
FIG. 6 is a sectional view of the interconnect beam 21, heel mass section
22 and toe mass section 30 of a number three iron club head taken at the
horizontal plane 18 intersecting the effective club head center of gravity
20. The vertical plane 23 is shown perpendicular to the club face 16 and
intersecting the effective center of gravity 20. The moment of inertia of
a beam is define as: I=bh.sup.3 /12. Although the present invention
specifies a minimum rearward h dimension 24 of 0.5 inch, the iron club
heads of the present invention will have a typical rearward beam dimension
24 relative to the club face of at least 0.75 inch. A high radius of
gyration club head that does not rigidly interconnect its heel-toe mass
sections, can not afford a maximized elongation of the sweet spot along
the heel-toe dimension.
FIG. 7 is a sectional view of the number three iron club head taken at the
vertical plane 23 passing through the effective center of gravity 20. The
sectional view shows the high moment of inertia beam 21 traversing through
the horizontal plane 18 at the point where the effective center of gravity
20 is located. As shown by dimension 24 relative to the club face 16 the
high moment of inertia beam 21 is seen to project substantially beyond the
rear boundary limit of the crown 35.
In the discussion of the present invention, the club head is in its normal
address position unless specified otherwise. Dynamic balancing is defined
as the case where the effective center of gravity of the club head is at
the midpoint of the club face toe and heel boundary limits and where,
M.sub.T .times.m.sub.T v.sub.T =M.sub.H .times.m.sub.H v.sub.H. Effective
center of gravity is the center of gravity determined by giving due
consideration to the different velocities of the toe and heel sections at
impact. The velocities of a rigid body can at any instant be described as
the sum of the velocity of a reference point of the body plus a velocity
due to rotation about an axis through the reference point.
While in the foregoing specification a detailed description of a specific
embodiment of the invention was set forth for illustrative purposes, it
will be understood that many of the parameters herein given may be varied
by those skilled in the art without departing from the spirit and scope of
the present invention.
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